Devtools Animations: Add cubic bezier easing editor for animations

Source/devtools/front_end/sdk/AnimationModel.js

 // Copyright (c) 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 
 /**
  * @constructor
  * @extends {WebInspector.SDKModel}
  * @param {!WebInspector.Target} target
  */
@@ skipping 335 matching lines @@
     keyframesRule: function()
     {
         return this._keyframesRule;
     },
 
     /**
      * @return {string}
      */
     easing: function()
     {
-        return this._payload.easing;
+        return this._easing || this._payload.easing;
+    },
+
+    /**
+     * @param {string} value
+     * @param {string} id
+     * @param {boolean=} callProtocol
+     */
+    setEasing: function(value, id, callProtocol)
+    {
+        this._easing = value;
+        if (callProtocol)

[dgozman, 2015/05/28 11:04:03]

What's the usecase for callProtocol == false?
When user changed the value, you have to call protocol method, right?

[samli, 2015/05/28 11:48:14]

CSS animations respond to updated styles and hence don't require a protocol
call. Invoking protocol will result in the protocol error we just added.

We could alternatively allow it to always call protocol and do nothing for CSS
animations.

+            this.target().animationAgent().setEasing(id, value);
     },
 
     __proto__: WebInspector.SDKObject.prototype
 }
 
 /**
  * @constructor
  * @extends {WebInspector.SDKObject}
  * @param {!WebInspector.Target} target
  * @param {!AnimationAgent.KeyframesRule} payload
@@ skipping 108 matching lines @@
 
     /**
      * @override
      * @param {string} playerId
      */
     animationPlayerCanceled: function(playerId)
     {
         this._animationModel.animationPlayerCanceled(playerId);
     }
 }